So far neither the public security ministry nor the foreign ministry in China has commented.

Though few details have emerged, the mysterious circumstances of Meng's disappearance have already prompted criticisms of Chinese authorities' lack of transparency. Zhou was one of the highest-profile figures caught up in President Xi Jinping's sprawling campaign against graft at all levels of government, military and state industry.

But Interpol has, in the past, denied this, saying its head does not intervene in day-to-day operations, which are handled by secretary-general Juergen Stock who is German.

News of his absence was swiftly followed by speculation that Meng - who is also Chinese deputy minister of public security - had been swept up in Beijing's secretive anti-corruption campaign.

The 36-year-old took to China's Twitter-like Weibo to acknowledge her wrongs, beg for her supporters" forgiveness, and apologise to "society, the friends who care about me, the public and the national tax authorities'. Mr Meng's term is scheduled to run until 2020.

His appointment caused concern among academics and human rights advocates, who feared he would abuse Interpol's powers to forcibly repatriate Chinese dissidents and fugitives.

Interpol staff can carry special passports to help speed deployment in emergency situations but that would not have given Meng any specific rights or immunity in his home country. Beijing has in the past pressed countries to arrest and deport to China citizens it accuses of crimes, from corruption to terrorism. The official in question suddenly drops out of the public eye and an alarm is raised that the person is "missing", usually by members of the public. Only at the behest of a country does the information go public via a "red notice", the closest thing to an global arrest warrant.